Bovine spongiform encephalopathy (BSE) or commonly known as the "mad cow disease" has plagued Europe for almost two decades back, but the threat it poses may be valid up to this day.
The contamination of mad cow disease may occur after eating meat contaminated with the disease. These affected people may be not showing any symptoms of the disease until 2 to 5 years from exposure or contamination.
BSE is caused by its infectious agent, a misshapen protein called prion. Its ability to convert normal protein to its misshapen characteristic and carry the disease between individuals are similar to that of a viral disease. These prions can cause a fatal neurodegenerative disease called variant Creutzfeldt-Jakob disease (vCJD).
Brain tissue reveals the presence of typical amyloid plaques found in a case of variant Creutzfeldt-Jakob disease (vCJD)
Thousands of Europeans are thought to be carrying this prion disease without showing any symptoms yet, and they can spread prions through blood donations.
There are still no standard method of detecting prions in the blood. Two teams from opposite sides of the world want to change that. They will be using a new method that is said to prove as highly accurate in giving results from samples of infected people and control group.
Analyses of discarded appendix and tonsil samples show that one in 2000 people in the United Kingdom carries the abnormal prions. With vCJD's long incubation period that can even go as far as 50 years as the longest ever reported, it's impossible to know how many people are going to eventually develop the disease.
Once symptoms occur, like depression
, hallucinations, dementia
and even loss of motor control, it can go about a year until the patient will succumb to the disease.
The new tests that were performed by the two groups used the technique that "amplifies prions by culturing them with normal proteins and then agitating them with sound waves," as described in Science Translational Medicine.
McGovern Medical School at the University of Texas Health Science Center in Houston, developed the technique which breaks off clumps of prions and converts their neighboring normal proteins. Claudio Soto, one of their neurobiologist explains further on how the method works. “Each can act as a seed to make this reaction go exponentially faster."
Soto's team tested blood from 14 vCJD patients and 137 controls which confirms presence of prions in vCJD patients and none of the control.
The second study at University of Montpellier in France which is led by microbiologist Daisy Bougard used the same method but they first captured prions in the sample using magnetic nanobeads. Their result confirmed 18 vCJD patients out of 256 samples, including 2 vCJD patients who were not showing symptoms before they donated blood.
Jonathan Wadsworth, a biochemist who studies prion disease at University College London who is not involved in the study said, "We have this ethical dilemma—how do you tell people they may have a fatal disease when we don’t know whether the test is specific?”
Both studies have to pursue prediction of false positives. Or else, using this method alone will deplete the blood donation rate.
Both teams are now working to validate their tests.
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